MEMS Malzeme Karakterizasyonu için Bütünleşik bir Elektrostatik Mikro Bükülme Test Yapısı Tasarımı ve Gerçekleştirilmesi

MEMS Malzeme Karakterizasyonu için Bütünleşik bir Elektrostatik Mikro Bükülme Test Yapısı Tasarımı ve Gerçekleştirilmesi

Because of the fabrication techniques, mechanical properties of the materials used in micro electromechanical systems should be determined by utilizing micro-scale test structures. In this study, a micro bending test structure, whose actuator, sample, and readout scale are integrally fabricated on a single chip is presented. Integrated fabrication of all components eliminates the alignment problem observed in similar systems. The structure relies on the principle of bending a double-clamped beam from its center by using an electrostatic comb drive. Deflection amount is determined by using image processing techniques on the read-out scale. Designed structures are fabricated by using silicon-oninsulator wafers. As a result of the tests, elastic modulus of silicon is determined as 136 GPa in accordance with the literature. 

___

  • [1] T. Yi and C.-J. Kim, Measurement of mechanical properties for MEMS materials, Measurement Science and Technology 10 (1999), 706–716.
  • [2] T. Tsuchiya, Evaluation of mechanical properties of MEMS materials and their standardization, Reliability of MEMS, Wiley-VCH 2008, 1–25.
  • [3] M. A. Haque and M. T. A. Saif, Microscale materials testing using MEMS actuators, Journal of Microelectromechanical Systems 10 (2001), 146–152.
  • [4] M. A. Haque and M. T. A. Saif, Mechanical behavior of 30-50 nm thick aluminum films under uniaxial tension, Scripta Materialia 47 (2002), 863–867.
  • [5] T. P. Weihs, S. Hong, J. C. Bravman and W. D. Nix, Mechanical deflection of cantilever microbeams: A new technique for testing the mechanical properties of thin films, Journal of Materials Research 3 (1988), 931–942.
  • [6] S.-H. Lee, J. W. Evans, Y. E. Pak, J. U. Jeon and D. Kwon, Evaluation of elastic modulus and yield strength of Al film using an electrostatically actuated test device, Thin Solid Films 408 (2002), 223–229.
  • [7] E. Yildirim, Development of Test Structures and Methods for Characterization of MEMS Materials, Master Thesis, Middle East Technical University, Ankara 2005.
  • [8] S. D. Senturia, Microsystem Design, Springer 2001.
  • [9] W. Young, R. Budynas and A. Sadegh, Roark’s Formulas for Stress and Strain, Mcgraw-Hill 2011.
  • [10] M. A. Hopcroft, W. D. Nix and T. W. Kenny, What is the Young’s modulus of silicon? Journal of Microelectromechanical Systems 19 (2010), 229–238.